Field of the Invention
The present invention relates to a power semiconductor device and a method for manufacturing the power semiconductor device, particularly, a power semiconductor device used for control of power and a method for manufacturing the power semiconductor device.
Description of the Background Art
Power semiconductor devices have been used for industrial devices, driving control devices for household appliances including motors, in-vehicle control devices for electric vehicles and hybrid vehicles, railway control devices, control devices for photovoltaic power generation, and the like. Accordingly, power semiconductor devices are required to handle high power. Such power semiconductor devices are disclosed in, for example, Patent Document 1 (Japanese Patent Laying-Open No. 2015-024443), Patent Document 2 (Japanese Patent Laying-Open No. 2012-178513) and Patent Document 3 (Japanese Patent Laying-Open No. 2013-220476).
In recent years, in response to increased environmental regulation, power semiconductor devices are required to achieve higher efficiency and more energy saving in consideration of environmental issues. Particularly, in in-vehicle control devices or railway control devices, in order to achieve energy saving and suppress loss involved in conversion of electrical energy, power semiconductor devices have begun to be used under a high-load environment (under a high-temperature environment) (increased Tj).
Accordingly, the power semiconductor devices are required to suppress the loss and operate with high efficiency even under the high-temperature environment. Specifically, a general operation temperature of a conventional power semiconductor device is Tj=125° C. or less or Tj=150° C. or less; however, in future, it is expected to operate a power semiconductor device under a high-temperature environment of Tj=175° C. or more or Tj=200° C. or more.